It has been known to form images by selectively crosslinking materials by applying light to a cross-linkable resin. The technique has been used for forming photoresists where, after uncrosslinked material has been removed, etching of metal or glass is carried out. The technique has also been used to form silk-screen or screen-printing materials where the uncrosslinked material is washed out of the screen to create the finished printing screen. Such techniques are disclosed in "Light Sensitive Systems" by J. Kosar, published by John Wiley and Sons, Inc., New York, 1965, and in "Screen Process Printing" by J.Stephens, published by Blueprint (an imprint of Chapman and Hall), London, 1996.
The prior techniques, while successful, are expensive as they require expensive light imaging apparatus. Further they require expensive resins that will cross-link when exposed to light. There is difficulty in forming thick coats of crosslinked polymer as the light can not penetrate through thick cross-linkable resins, particularly when they are coloured. Further, only very expensive imaging equipment could accurately produce fine quality images.
In forming of signs and posters there is a need for signs that are low in cost but very resistant to damage and wear. There is a need for small businesses and in the home to make posters, signs and notices that will last and are suitable for outdoor use. While the making of banners and posters are well known, they are on paper that in large pieces can not be hung and are easily damaged by wind, rain, and handling.